Recoil starter assembly for an engine

ABSTRACT

An engine includes an engine cover, a blower fan, and a recoil starter having a cover. The engine cover includes an inlet aperture and is configured to house working components of the engine. The blower fan is configured to disperse air received through the inlet aperture to cool the working components of the engine. The recoil starter cover has an opening for air to pass through and is fastened to the underside of the engine cover.

BACKGROUND

The present invention relates generally to the field of small, internalcombustion engines, such as those engines that may be used to poweroutdoor power equipment including, for example, walk-behind lawn mowers,snow throwers, and pressure washers. More specifically, the presentinvention relates to the engine cover, the recoil starter, and the aircooling system of an engine.

Small, internal combustion engines often include a recoil starter. Anoperator pulls a rope attached to a wheel coupled to the crankshaft ofthe engine, to rotate the crankshaft. Rotation of the crankshaft, inturn, initiates combustion processes of the engine by facilitating themovement of air and fuel through the engine and simultaneously producingsparks in the combustion chamber via the ignition system of the engine.Typically the recoil starter further includes an automatic rewind in theform of a torsion spring that recoils the rope after the operator hascompleted a pull. In some cases, the engine may require several pulls tostart. When the engine is running fast enough, the combustion processesautomatically drive the crankshaft without assistance from the recoilstarter.

During manufacturing of the engine, installation of the recoil startermay take significant time and effort. In some instances, the recoilstarter may be manually screwed onto the top of an engine. In suchcases, the number and strength of the screws must be strong enough tohold the recoil starter to the top of the engine when the operator ispulling the rope.

SUMMARY

One embodiment of the invention relates to an engine, which includes anengine cover, a blower fan, and a recoil starter having a cover. Theengine cover includes an inlet aperture and is configured to houseworking components of the engine. The blower fan is configured todisperse air received through the inlet aperture to cool the workingcomponents of the engine. The recoil starter cover has an opening forair to pass through and is fastened to the underside of the enginecover.

Another embodiment of the invention relates to an engine, which includesan engine cover, a recoil starter having a cover, a blower fan, and anair deflector. The engine cover includes an inlet aperture and isconfigured to house working components of the engine. The recoil startercover has an opening for air to pass through and is configured to spanthe inlet aperture of the engine cover. The blower fan is configured todisperse air received through the inlet aperture to cool the workingcomponents of the engine. The air deflector is configured to bepositioned proximate to the underside of the recoil starter cover and toextend from a rim of the inlet aperture toward the center of the inletaperture, partially over the inlet aperture. The air deflector helpsdirect air dispersed by the blower fan toward the working components ofthe engine.

Yet another embodiment of the invention relates to a method ofmanufacturing an engine. The method includes fastening a recoil starterto an underside of an engine cover such that the recoil starter spans aninlet aperture of the engine cover. Contact between the underside of theengine cover and the recoil starter provides a load-bearing interfaceduring starting of the engine.

Alternative exemplary embodiments relate to other features andcombinations of features as may be generally recited in the claims.

BRIEF DESCRIPTION OF THE FIGURES

The disclosure will become more fully understood from the followingdetailed description, taken in conjunction with the accompanyingfigures, in which:

FIG. 1 is perspective view of an engine according to an exemplaryembodiment of the invention.

FIG. 2 is a schematic diagram of an engine, such as the engine of FIG.1, according to an exemplary embodiment of the invention.

FIG. 3 is a perspective view of a cover for a recoil starter accordingto an exemplary embodiment of the invention.

FIG. 4 is a exploded view of the recoil starter cover of FIG. 3 beinginserted into an engine cover according to an exemplary embodiment ofthe invention.

FIG. 5 is a perspective view of portions of the recoil starter cover ofFIG. 3 and engine cover of FIG. 4 fastened together.

FIG. 6 is an exploded view of a recoil starter cover and an airdeflector being inserted into an engine cover according to an exemplaryembodiment of the invention.

FIG. 7 is a perspective view of the recoil starter cover, air deflector,and engine cover of FIG. 6 fastened together.

FIG. 8 is a sectional view of portions of the recoil starter cover, airdeflector, and engine cover of FIG. 6 fastened together, taken alongline 8-8 of FIG. 7.

FIG. 9 is a perspective view of a recoil starter cover, air deflector,and engine cover fastened together according to another exemplaryembodiment of the invention.

FIG. 10 is a sectional view of portions of the recoil starter cover, airdeflector, and engine cover of FIG. 9 fastened together, taken alongline 10-10 of FIG. 9.

DETAILED DESCRIPTION

Before turning to the figures, which illustrate the exemplaryembodiments in detail, it should be understood that the presentapplication is not limited to the details or methodology set forth inthe description or illustrated in the figures. It should also beunderstood that the terminology is for the purpose of description onlyand should not be regarded as limiting.

Referring to FIGS. 1-2, an engine 110 includes an engine cover 112(e.g., shroud) configured to house working components of the engine 110,such as a blower fan 114 (e.g., combination fan and flywheel), acrankshaft 116, a crankcase 118, or other components. The engine 110further includes a muffler 120 and heat shield 122, a cover 124 forrocker arms of an overhead valve system, an air intake 126 with primerbulb 128, a gas tank 130 and cap 132, a cap 134 for an oil chute, and arecoil starter assembly 136.

The recoil starter assembly 136 includes a cover 138 (e.g., recoilstarter cover), a handle 140 connected to a rope 142, and a spool 144(e.g., wheel, sheave) for the rope 142. The spool 144 is coupled to thecrankshaft 116 of the engine 110. To start the engine, an operator pullsthe rope 142 to rotate the crankshaft 116 and initiate combustionprocesses of the engine 110. According to an exemplary embodiment, therecoil starter cover 138 includes openings 146 through which air maypass into the interior 148 of the engine cover 112 to be dispersed bythe blower fan 114 to cool the working components of the engine 110.

The recoil starter assembly 136 may be coupled to the crankshaft 116 ina variety of different ways, such as directly, using a ratchetingmember, or indirectly via intermediate gearing, with or without aratcheting member. According to an exemplary embodiment, a ratchet(e.g., including “dogs”) of the rewind extends, engages, and rotates astarter cup when the rewind rope is pulled. The starter cup thencommunicates the rotation to the crankshaft. When the rope issubsequently released, the rope automatically rewinds and the ratchetretracts and disengages the starter cup. In other embodiments, otherconnection systems and features may be used, such as a clutch toselectively engage the starter with the crankshaft.

According to an exemplary embodiment, the engine 110 is a small,internal combustion engine designed for outdoor power equipment, such aswalk-behind lawn mowers, snow throwers, pressure washers, portablegenerators, go-carts, rotary tillers, and other such equipment. In someembodiments, the engine 110 is vertically shafted; while in otherembodiments, the engine is horizontally shafted. The engine 110 mayinclude one or more cylinders, and may operate on a two- or four-strokecycle. In contemplated embodiments, the engine 110 may include anelectric starter motor with an air intake piece for the blower fan inplace of the recoil starter cover 138 shown in FIGS. 1-2, where the airintake piece is fastened to the engine cover 112 according to teachingsdisclosed herein.

Referring now to FIG. 3, a recoil starter cover 210 has a generallyround shape and includes openings 212 through which air may pass. Inother embodiments, the shape of the recoil starter cover is square,polygonal, or otherwise shaped. The openings 212 may be of variousshapes and configurations, including a mesh or screen. According to anexemplary embodiment, the recoil starter cover 210 is formed from asingle continuous material, such as injection molded from plastic orstamped from metal. In some embodiments, the recoil starter cover 210includes a boss 214 (e.g., pin) for a spool (see, e.g., spool 144 asshown in FIG. 2), where the boss 214 may be integrally formed with therecoil starter cover 210 or simply fastened thereto.

Referring to FIG. 4, the recoil starter cover 210 is configured to befastened to an engine cover 216, which is shown in an upside-downorientation in FIG. 4. The engine cover 216 includes an intake aperture218 (e.g., opening, hole) in the center of the top of the engine cover216, above the crankshaft (see, e.g., crankshaft 116 as shown in FIG.2). The recoil starter cover 210 is configured to be fastened to theunderside 220 (e.g., engine-side, bottom) of the engine cover 216, asshown in FIG. 4, such that the recoil starter cover 210 spans (e.g.,fills, is positioned within) and extends through the intake aperture218. In other contemplated embodiments, an intake aperture may beelsewhere positioned in the engine cover.

According to an exemplary embodiment, the recoil starter cover 210includes a flange 222 (e.g., lip, extension) projecting outward from aside of the recoil starter cover 210. The flange 222 is sized to bewider than the intake aperture 218, preventing the recoil starter cover210 from passing fully through the intake aperture 218 when insertedfrom the underside 220 of the engine cover 216. The flange 222 is thenconfigured to contact a rim 224 of the intake aperture 218. Incontemplated embodiments, the contact may be indirect, such as in caseswhere a gasket, glue, or other intermediate element is positionedbetween the flange 222 and rim 224, such as to establish an air seal orto fasten the flange 222 and rim 224 together. Contact between the rim224 and flange 222 provides a load-bearing interface during operation ofthe recoil starter, which may be stronger or more reliable thaninterfaces provided by other fastening methods, such as gluing,screwing, clipping, etc. the recoil starter to the top of the enginecover. The load-bearing interface may help to keep the recoil startercover attached to the engine despite loading caused by operation of therecoil starter. However, in contemplated embodiments, the recoil startercover may be fastened to the top of the engine cover via other suchfastening methods.

Referring to FIGS. 4-5, the engine cover 216 and recoil starter cover210 include a fastening system 230 (FIG. 5) for attachment of the recoilstarter cover 210 to the engine cover 216. In some embodiments, thefastening system 230 includes first and second parts 232, 234, where oneof the parts 232 is integrally formed with the engine cover 216 (e.g.,molded with, stamped with, of the same continuous body) and the other ofthe parts 234 is integrally formed with the recoil starter cover 210.Integrally forming the parts 232, 234 of the fastening system 230 withthe engine cover 216 and recoil starter cover 210 may reduce the needfor additional fastening components (e.g., screws, washers, nuts, bolts,glue) which may get lost, fall out, take extra time to install orremove, etc. However, in other embodiments, the engine cover 216 andrecoil starter cover 210 may be fastened together with fasteningcomponents that are not integrally connected to the engine cover 216 orrecoil starter cover 210.

In some embodiments, the first and second parts 232, 234 of thefastening system 230 include a hook 236 and a receiving surface 238(e.g., catch, ledge) for the hook 236. The hook 236 may face toward thecenter of the intake aperture 218, away therefrom, or may be otherwiseoriented, where the receiving surface 238 is correspondingly oriented toreceive the hook 236. In some embodiments, the receiving surface 238 isthe bottom rim of the recoil starter cover 210. In other embodiments,the receiving surface is a hole, a groove, or part of a flange orextension from the side of the recoil starter cover 210. As shown inFIG. 4, the fastening system 230 may include more than one hook 236,such as three or more hooks 236 positioned around the intake aperture218; or in other contemplated embodiments, around the outer periphery ofthe recoil starter cover 210.

According to an exemplary embodiment, the top 240 of the hook 236includes an inclined surface. As such, movement of the recoil startercover 210 into the intake aperture 218 of the engine cover 216, duringassembly of the engine, provides an orthogonal component to the contactforce between the top 240 of the hook 236 and a contacting surface 242.The orthogonal component causes the hook 236 to temporarily deflect(e.g., flex, move out of the way of), allowing the recoil starter cover210 to pass into a fastened position in the intake aperture 218 of theengine cover 216, as shown in FIG. 5. In contemplated embodiments, thesurface 242 contacting the top 240 of the hook 236 may also deflect.Alternatively, the contacting surface may be inclined and deflect, whilethe top of the hook may not be inclined. Once the recoil starter haspassed to the fastened position, the hook 236 then engages the receivingsurface 238. To detach the recoil starter cover 210 from the enginecover 216, the hook 236 may be manually deflected and the recoil startercover 210 may then be lifted away from the engine cover 216.

According to an exemplary embodiment, the hook 236 of the first part 232of the fastening system 230 is part of the engine cover 216, and thereceiving surface 238 of the second part 234 of the fastening system 230is on the recoil starter cover 210. In other embodiments, positioning ofthe hook and receiving surface is reversed. In still other embodiments,each of the engine cover and recoil starter cover includes a hook and areceiving surface.

In some embodiments, guide structures, such as pins 226 andcorresponding holes 228, may be used with the fastening system 230 toguide the attachment of the recoil starter cover 210 to the engine cover216. In other embodiments, pins may be used to facilitate heat stakingof the recoil starter cover to the engine cover. In still otherembodiments, pins or other guide structures are not included (seegenerally FIGS. 6-8).

Referring now to FIGS. 6-8, an engine cover 310, recoil starter cover312, and air deflector 314 (e.g., cooling ring) may be fastened together(FIG. 7). According to an exemplary embodiment, the recoil starter cover312 may be fastened into a position spanning an intake aperture 316 inthe engine cover 310. The air deflector 314 may be fastened proximate to(e.g., adjacent to) the recoil starter cover 312 such that the recoilstarter cover 312 is between the air deflector 314 and a rim 318 of theintake aperture 316 of the engine cover 310.

The air deflector 314 shown in FIGS. 6-8 generally extends from the rim318 of the intake aperture 316 toward the center of the intake aperture316. In embodiments using a centrifugal blower fan (see, e.g., blowerfan 114 as shown in FIG. 2), air flow generated beneath the engine cover310 by the blower fan may be at a higher pressure proximate to the sidesof the engine, as opposed to the center of the engine below the intakeaperture 316 (see generally FIG. 2). However, without the air deflector,some air flow provided by the blower fan may flow out of the intakeaperture 316, especially close to the rim 318 of the intake aperture316, reducing the amount of cooling air directed to the workingcomponents of the engine. Accordingly, the air deflector 314 isconfigured to help direct air dispersed by the blower fan toward theworking components of the engine by limiting (e.g., reducing) the flowof air out of the intake aperture 316.

In some embodiments, the intake aperture 316 is round and the airdeflector 314 extends from the rim 318 of the intake aperture 316 towardthe center of the intake aperture 316 a distance that is less than halfthe radius of the intake aperture 316, providing an opening through thecenter of the intake aperture 316 with sufficient area for air to flowthrough the intake aperture 316 to the blower fan to cool the engine.However, in some embodiments, the air deflector 314 extends at least aneighth of the radius, such as about a quarter of the radius, from therim 318 toward the center of the intake aperture 316 in order tosufficiently limit air flow out of the intake aperture 316. In otherembodiments, an air deflector extends further than half the radiustoward the center or less than an eighth of the radius toward thecenter.

According to an exemplary embodiment, the air deflector 314 extendsaround the full periphery of the intake aperture 316. In otherembodiments, the air deflector extends only partially around theperiphery of the air intake, such as around portions of the peripherycorresponding to the rear and lateral sides of the engine. Incontemplated embodiments, the air deflector may not be round.

Referring to FIG. 8, the air deflector 314 may be fastened to the enginecover 310 in a manner as described above with regard to the attachmentof the recoil starter cover 210 to the engine cover 216 (see FIG. 5). Insome such embodiments, the recoil starter cover 312 is fastened to theengine cover 310 with one set of hooks 320 and the air deflector 314 isfastened on top of the recoil starter cover 312 with a second set ofhooks 322, so that the air deflector 314 is configured to be insertedand removed from the engine cover 310 separately from the recoil startercover 312. In other contemplated embodiments, the air deflector may beengaged by the same hooks that engage the receiving surface on therecoil starter cover. In still other embodiments, the air deflector maybe heat staked, glued, or otherwise fastened to the engine cover, therecoil starter cover, or both. In some contemplated embodiments, the airdeflector is integrated with (e.g., fastened to, integrally formed with)the recoil starter cover prior to attachment of either the recoilstarter cover or the air deflector to the engine cover.

In the embodiment shown in FIGS. 6-8, pins and corresponding holes inthe recoil starter cover and air deflector, or other such guide orfastening structures, are not included. By contrast, the embodiment inFIGS. 9-10 includes a guiding structure for an air deflector 422 in theform of bosses 410 that are integrally formed with and extend from arecoil starter cover 412. The bosses 410 engage corresponding holes inthe air deflector 422 during assembly.

Still referring to FIGS. 9-10, a method of manufacturing an engineincludes fastening the recoil starter cover 412 to an underside of anengine cover 414 of the engine such that the recoil starter cover 412spans an inlet aperture of the engine cover 414. Contact between theunderside of the engine cover 414 and the recoil starter cover 412provides a load-bearing interface during operation of the recoilstarter.

A fastening system 416 may be used for fastening the recoil startercover 412 to the underside of the engine cover 414 by engaging a hook418 with a receiving surface 420. The hook 418, in some embodiments, isintegrally formed with one of the recoil starter cover 412 and theengine cover 414, while the receiving surface 420 is integrally formedwith the other of the recoil starter cover 412 and the engine cover 414.

In some embodiments, the manufacturing method further includes fasteningthe air deflector 422, as described above, proximate to an underside ofthe recoil starter cover 412. The air deflector 422 extends from a rimof the inlet aperture toward the center of the inlet aperture, partiallyover the inlet aperture. Accordingly, the air deflector 422 helps todirect air dispersed by a blower fan of the engine toward workingcomponents of the engine.

The construction and arrangements of the engine, as shown in the variousexemplary embodiments, are illustrative only. Although only a fewembodiments have been described in detail in this disclosure, manymodifications are possible (e.g., variations in sizes, dimensions,structures, shapes and proportions of the various elements, values ofparameters, mounting arrangements, use of materials, colors,orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter described herein. Someelements shown as integrally formed may be constructed of multiple partsor elements, the position of elements may be reversed or otherwisevaried, and the nature or number of discrete elements or positions maybe altered or varied. The order or sequence of any process, logicalalgorithm, or method steps may be varied or re-sequenced according toalternative embodiments. Other substitutions, modifications, changes andomissions may also be made in the design, operating conditions andarrangement of the various exemplary embodiments without departing fromthe scope of the present invention.

1. An engine, comprising: an engine cover configured to house workingcomponents of the engine, wherein the engine cover comprises an inletaperture; a blower fan configured to disperse air received through theinlet aperture to cool the working components of the engine; and arecoil starter having a cover with an opening for air to pass through,wherein the recoil starter cover is fastened to the underside of theengine cover.
 2. The engine of claim 1, further comprising a fasteningsystem for attachment of the recoil starter cover to the engine cover,wherein the engine cover comprises a first part of the fastening systemthat is integrally formed with the engine cover, and wherein the recoilstarter cover comprises a second part of the fastening system that isintegrally formed with the recoil starter cover.
 3. The engine of claim2, wherein one of the first and second parts comprises a hook, andwherein the other of the first and second parts comprises a receivingsurface for engaging the hook to fasten the recoil starter cover to theunderside of the engine cover.
 4. The engine of claim 3, wherein a topof the hook is inclined toward a distal end of the hook, and wherein theother of the first and second parts further comprises a contact surfacefor contacting the top of the hook during fastening of the recoilstarter cover to the underside of the engine cover such that the hookflexes as the first and second parts engage one another.
 5. The engineof claim 4, wherein the engine cover includes the hook and the recoilstarter cover includes the receiving surface.
 6. The engine of claim 5,wherein the recoil starter cover further comprises a flange extendinglaterally from a side of the recoil starter cover.
 7. The engine ofclaim 6, wherein the engine cover further comprises a rim of the inletaperture, and wherein the flange of the recoil starter cover isconstrained between the hook and the rim, whereby contact between therim and the flange provides a load-bearing interface during starting ofthe engine.
 8. The engine of claim 7, further comprising an airdeflector proximate to the recoil starter cover and extending from therim of the inlet aperture toward the center of the inlet aperture,partially over the inlet aperture.
 9. The engine of claim 8, wherein therecoil starter cover is fastened between the air deflector and the rimof the inlet aperture of the engine cover.
 10. The engine of claim 9,wherein the air deflector is fastened to the underside of the enginecover.
 11. The engine of claim 10, wherein the engine cover furthercomprises an additional hook for the air deflector that is configured toengage a receiving surface of the air deflector, whereby the airdeflector is configured to be inserted and removed from the engine coverseparately from the recoil starter cover.
 12. An engine, comprising: anengine cover configured to house working components of the engine,wherein the engine cover comprises an inlet aperture; a recoil starterhaving a cover configured to span the inlet aperture of the enginecover, wherein the recoil starter cover has an opening for air to passthrough; a blower fan configured to disperse air received through theinlet aperture to cool the working components of the engine; and an airdeflector configured to be positioned proximate to the underside of therecoil starter cover and to extend from a rim of the inlet aperturetoward the center of the inlet aperture, partially over the inletaperture, whereby the air deflector directs air dispersed by the blowerfan toward the working components of the engine.
 13. The engine of claim12, wherein the air deflector extends fully around the rim of the inletaperture.
 14. The engine of claim 12, wherein the air deflector isfastened to at least one of the engine cover and the recoil startercover from an underside thereof.
 15. The engine of claim 14, wherein therecoil starter cover is fastened to the underside of the engine cover.16. The engine of claim 15, wherein the recoil starter cover is fastenedbetween the air deflector and the rim of the inlet aperture of theengine cover.
 17. The engine of claim 16, wherein the air deflector ishooked to the underside of the engine cover.
 18. A method ofmanufacturing an engine, comprising fastening a recoil starter to anunderside of an engine cover such that the recoil starter spans an inletaperture of the engine cover, whereby contact between the underside ofthe engine cover and the recoil starter provides a load-bearinginterface during starting of the engine.
 19. The method of claim 18,further comprising using a fastening system for fastening the recoilstarter to the underside of the engine cover by engaging a hook, whichis integrally formed with one of the recoil starter and the enginecover, with a receiving surface of the other of the recoil starter andthe engine cover.
 20. The method of claim 19, further comprisingfastening an air deflector proximate to an underside of a cover of therecoil starter, wherein the air deflector then extends from a rim of theinlet aperture toward the center of the inlet aperture, partially overthe inlet aperture, whereby the air deflector facilitates direction ofair dispersed by a blower fan of the engine toward working components ofthe engine.